/**
* \brief initialize mjpeg encoder
*
* This routine is to set up the parameters and initialize the mjpeg encoder.
* It does all the initializations needed of lower level routines.
* The formats accepted by this encoder is YUV422P and YUV420
*
* \param w width in pixels of the image to encode, must be a multiple of 16
* \param h height in pixels of the image to encode, must be a multiple of 8
* \param y_rsize size of each plane row Y component
* \param y_rsize size of each plane row U component
* \param v_rsize size of each plane row V component
* \param cu "cheap upsample". Set to 0 for YUV422 format, 1 for YUV420 format
* when set to 1, the encoder will assume that there is only half th
* number of rows of chroma information, and every chroma row is
* duplicated.
* \param q quality parameter for the mjpeg encode. Between 1 and 20 where 1
* is best quality and 20 is the worst quality.
* \param b monochrome flag. When set to 1, the mjpeg output is monochrome.
* In that case, the colour information is omitted, and actually the
* colour planes are not touched.
*
* \returns an appropriately set up jpeg_enc_t structure
*
* The actual plane buffer addreses are passed by jpeg_enc_frame().
*
* The encoder doesn't know anything about interlacing, the halve height
* needs to be passed and the double rowstride. Which field gets encoded
* is decided by what buffers are passed to mjpeg_encode_frame()
*/
static jpeg_enc_t *jpeg_enc_init(int w, int h, int y_rsize,
int u_rsize, int v_rsize,
int cu, int q, int b) {
jpeg_enc_t *j;
int i = 0;
VERBOSE("JPEG encoder init: %dx%d %d %d %d cu=%d q=%d bw=%d\n",
w, h, y_rsize, u_rsize, v_rsize, cu, q, b);
j = av_mallocz(sizeof(jpeg_enc_t));
if (j == NULL) return NULL;
j->s = av_mallocz(sizeof(MpegEncContext));
if (j->s == NULL) {
av_free(j);
return NULL;
}
/* info on how to access the pixels */
j->y_rs = y_rsize;
j->u_rs = u_rsize;
j->v_rs = v_rsize;
j->s->width = w; // image width and height
j->s->height = h;
j->s->qscale = q; // Encoding quality
j->s->out_format = FMT_MJPEG;
j->s->intra_only = 1; // Generate only intra pictures for jpeg
j->s->encoding = 1; // Set mode to encode
j->s->pict_type = AV_PICTURE_TYPE_I;
j->s->y_dc_scale = 8;
j->s->c_dc_scale = 8;
/*
* This sets up the MCU (Minimal Code Unit) number
* of appearances of the various component
* for the SOF0 table in the generated MJPEG.
* The values are not used for anything else.
* The current setup is simply YUV422, with two horizontal Y components
* for every UV component.
*/
//FIXME j->s->mjpeg_write_tables = 1; // setup to write tables
j->s->mjpeg_vsample[0] = 1; // 1 appearance of Y vertically
j->s->mjpeg_vsample[1] = 1; // 1 appearance of U vertically
j->s->mjpeg_vsample[2] = 1; // 1 appearance of V vertically
j->s->mjpeg_hsample[0] = 2; // 2 appearances of Y horizontally
j->s->mjpeg_hsample[1] = 1; // 1 appearance of U horizontally
j->s->mjpeg_hsample[2] = 1; // 1 appearance of V horizontally
j->cheap_upsample = cu;
j->bw = b;
init_avcodec();
// Build mjpeg huffman code tables, setting up j->s->mjpeg_ctx
if (ff_mjpeg_encode_init(j->s) < 0) {
av_free(j->s);
av_free(j);
return NULL;
}
/* alloc bogus avctx to keep MPV_common_init from segfaulting */
j->s->avctx = avcodec_alloc_context();
if (j->s->avctx == NULL) {
av_free(j->s);
av_free(j);
return NULL;
}
// Set some a minimum amount of default values that are needed
// Indicates that we should generated normal MJPEG
j->s->avctx->codec_id = AV_CODEC_ID_MJPEG;
// Which DCT method to use. AUTO will select the fastest one
j->s->avctx->dct_algo = FF_DCT_AUTO;
j->s->intra_quant_bias= 1<<(QUANT_BIAS_SHIFT-1); //(a + x/2)/x
// indicate we 'decode' to jpeg 4:2:2
j->s->avctx->pix_fmt = PIX_FMT_YUVJ422P;
j->s->avctx->thread_count = 1;
/* make MPV_common_init allocate important buffers, like s->block
* Also initializes dsputil */
if (ff_MPV_common_init(j->s) < 0) {
av_free(j->s);
av_free(j);
return NULL;
}
/* correct the value for sc->mb_height. MPV_common_init put other
* values there */
j->s->mb_height = j->s->height/8;
j->s->mb_intra = 1;
// Init q matrix
j->s->intra_matrix[0] = ff_mpeg1_default_intra_matrix[0];
for (i = 1; i < 64; i++)
j->s->intra_matrix[i] = av_clip_uint8(
(ff_mpeg1_default_intra_matrix[i]*j->s->qscale) >> 3);
// precompute matrix
convert_matrix(j->s, j->s->q_intra_matrix, j->s->q_intra_matrix16,
j->s->intra_matrix, j->s->intra_quant_bias, 8, 8);
/* Pick up the selection of the optimal get_pixels() routine
* to use, which was done in MPV_common_init() */
get_pixels = j->s->dsp.get_pixels;
return j;
}
/* The encoder doesn't know anything about interlacing, the halve height
* needs to be passed and the double rowstride. Which field gets encoded
* is decided by what buffers are passed to mjpeg_encode_frame */
jpeg_enc_t *jpeg_enc_init(int w, int h, int y_psize, int y_rsize,
int u_psize, int u_rsize, int v_psize, int v_rsize,
int cu, int q, int b) {
jpeg_enc_t *j;
int i = 0;
mp_msg(MSGT_VO, MSGL_V, "JPEnc init: %dx%d %d %d %d %d %d %d\n",
w, h, y_psize, y_rsize, u_psize,
u_rsize, v_psize, v_rsize);
j = av_malloc(sizeof(jpeg_enc_t));
if (j == NULL) return NULL;
j->s = av_malloc(sizeof(MpegEncContext));
memset(j->s,0x00,sizeof(MpegEncContext));
if (j->s == NULL) {
av_free(j);
return NULL;
}
/* info on how to access the pixels */
j->y_ps = y_psize;
j->u_ps = u_psize;
j->v_ps = v_psize;
j->y_rs = y_rsize;
j->u_rs = u_rsize;
j->v_rs = v_rsize;
j->s->width = w;
j->s->height = h;
j->s->qscale = q;
j->s->out_format = FMT_MJPEG;
j->s->intra_only = 1;
j->s->encoding = 1;
j->s->pict_type = I_TYPE;
j->s->y_dc_scale = 8;
j->s->c_dc_scale = 8;
//FIXME j->s->mjpeg_write_tables = 1;
j->s->mjpeg_vsample[0] = 1;
j->s->mjpeg_vsample[1] = 1;
j->s->mjpeg_vsample[2] = 1;
j->s->mjpeg_hsample[0] = 2;
j->s->mjpeg_hsample[1] = 1;
j->s->mjpeg_hsample[2] = 1;
j->cheap_upsample = cu;
j->bw = b;
/* if libavcodec is used by the decoder then we must not
* initialize again, but if it is not initialized then we must
* initialize it here. */
if (!avcodec_inited) {
/* we need to initialize libavcodec */
avcodec_init();
avcodec_register_all();
avcodec_inited=1;
}
if (ff_mjpeg_encode_init(j->s) < 0) {
av_free(j->s);
av_free(j);
return NULL;
}
/* alloc bogus avctx to keep MPV_common_init from segfaulting */
j->s->avctx = calloc(sizeof(*j->s->avctx), 1);
/* Set up to encode mjpeg */
j->s->avctx->codec_id = CODEC_ID_MJPEG;
/* make MPV_common_init allocate important buffers, like s->block */
j->s->avctx->thread_count = 1;
if (MPV_common_init(j->s) < 0) {
av_free(j->s);
av_free(j);
return NULL;
}
/* correct the value for sc->mb_height */
j->s->mb_height = j->s->height/8;
j->s->mb_intra = 1;
j->s->intra_matrix[0] = ff_mpeg1_default_intra_matrix[0];
for (i = 1; i < 64; i++)
j->s->intra_matrix[i] = av_clip_uint8(
(ff_mpeg1_default_intra_matrix[i]*j->s->qscale) >> 3);
convert_matrix(j->s, j->s->q_intra_matrix, j->s->q_intra_matrix16,
j->s->intra_matrix, j->s->intra_quant_bias, 8, 8);
return j;
}